JavaScript Fetch API: how to store data in variable outside

Asked Aug 01 '19 at 08:19

Active Aug 01 '19 at 08:21

Viewed 29 times

Below is my code. I want to store the fetched JSON data in a variable outisde of the function scope. How can I do that? Also, if I want to run some functions on the fetched JSON data, am I supposed to do them inside .then()?

let jsondata;

fetch('https://api.myjson.com/bins/wa759')
  .then(function(response) {
    return response.json();
  })
  .then(function(myJson) {
    console.log(JSON.stringify(myJson));
    jsondata = myJson;
  });

  console.log("test");
  console.log(jsondata);

This logs

> Hello (corresponding to `console.log("test");`)
> undefined (corresponding to `console.log(jsondata);`)
> (the entire JSON data)

edited Aug 01 '19 at 08:21

asked Aug 01 '19 at 08:19

Leonard

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2

Note that `fetch()` is `async` and `console.log(jasondata)` would not await for `jasondata` to be changed. That's why you get undefined. – Mirakurun Aug 01 '19 at 08:21
1

Yes, its a good idea that whatever you want to do with jsondata, do it inside .then – Monika Mangal Aug 01 '19 at 08:27
You can create a custom `Promise` object and resolve it in `fetch(...).then()` – Aditya Bhave Aug 01 '19 at 08:31

JavaScript Fetch API: how to store data in variable outside

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